The data storage industry is at a crossroads. Storage needs are expanding at a rapid pace, making it difficult for businesses to keep up with the growing demands. In many cases, the amount of data stored is doubling every two years—filling up recently installed storage devices and making it difficult to serve the data at the performance level expected. Data centers are filling up, running out of storage, and often continue to add more disk to existing systems that are already bogged down by increased traffic and demands for faster operations.
The current approach of frequently replacing existing NAS with a next generation device is not only very costly to an enterprise, but also generates significant work for IT professionals who must manage migration of data from the “old” NAS device to the new, faster and bigger, NAS devices. Adding space-saving features, such as deduplication or compression, furthers slow performance. Adding solid-state drives (SSDs) allows for better performance, but does not solve the space issue and substantially increases cost. Cloud storage by itself solves for the space issue, but provides markedly lower performance and is not a panacea in terms of cost due to per-megabyte access and storage charges.
In addition to the above practical issues, replacing existing NAS can often mean an upfront cost of over $20,000 plus ongoing maintenance. On top of that initial capital expense comes the labor cost involved in migrating the existing data off the existing NAS onto the new NAS device and then reconfiguring every client to point to the new repository, together with the associated service disruption to users of the reconfigured storage. Furthermore, storage administrators often do not have the time or expertise to implement the newest solutions, exacerbating the already difficult situation. The labor required in adding more rack space, power, and cooling, as well as migrating the existing data is often overlooked, adding to their workloads in time and cost.
Further, migration technologies of the HSM form (Hierarchical Storage Management) typically migrate only whole files, and migration is based on file system free space. As the file system fills up, files are migrated and the file inode is modified to point to the current location of the migrated content. HSM is implemented inside the file system (typically kernel-resident) and is specific to that file system type.